The frontend and backend are two separate apps.
The frontend contains the final version of the app. It is a create-react-app generated project, all validation and business logic happen on frontend. It is my own implementation of generating address.
The backend is my first implementation of the app, it is a backend server written in NestJS (all logic on backend) and it provide a swagger for user to interactive with it. It is using hdkey and bitcoinjs-lib to generate address.
cd frontend
yarn install
yarn start
Then, you can visit the app on http://localhost:3000
cd backend
yarn install
yarn start
Then, you can visit the API swagger on http://localhost:3001/api